Outer Limits 4x4 Board

I have access to a custom intake plenum similar to this...

http://img.photobucket.com/albums/v114/ ... A71768.jpg

i was wandering a few things about them. THIS WILL BE BOLT ON ONLY, NO ADJUSTMENTS TO MOTOR AT ALL. the motor is a td42t running 14psi boost and full 3in exhaust.

1. will it be beneificial to power/torque?
2. will it increase/decrease/leave EGT's?
3. use more or less fuel?
4. any other advantages/disadvantages to the way i want to do it?

would getting it re-tuned make a lot of difference. could i do it at a later date? any harm in running it as a bolt on for now...tune later?

cheers

PAUL

vanbox wrote: 1. will it be beneificial to power/torque?

It will change your power and torque. It depends on how it is constructed inside as to how the airflow is changed.

vanbox wrote: 2. will it increase/decrease/leave EGT's?

It shouldn't do anything to your EGT's as this there is minimal cooling of the intake air.

vanbox wrote:3. use more or less fuel?

This will only change how much fuel you use depending on the effects of question 1. How ever it will be minimal.

vanbox wrote:4. any other advantages/disadvantages to the way i want to do it?

The main advantage of a large plenum chamber is to calm the air and direct it to the right places for the best efficiency. It won't cool the air or change the fuel input enough to make a real difference.

vanbox wrote:would getting it re-tuned make a lot of difference. could i do it at a later date? any harm in running it as a bolt on for now...tune later?

If you are running 14psi already without tuning it then your engine is running lean and you are mostly wasting your time with the higher boost. If you run this plenum chamber then definately tune the engine. You may find that your fuel pump isn't delivering enough fuel and you'll ruin your engine if you lean it out. You haven't said if it is a GQ or GU fuel pump. They are different. You can get a little more out of a GU pump before having to change internal parts.

sorry. its a 2001 GU and has had a tune with the 14psi and exhaust. but has only recently been done....the reason i asked that question is because i dont want to have to have another tune after putting the plenum on if its not necessary.

cheers

PAUL

Running 14 psi, 3in exhaust and tuned then you can't do much else to it other than start changing internals of the fuel pump as it would be close to being maxed out anyway so you won't have to retune. The plenum may or may not have an adverse effect on your power and torque though.

toughnut wrote:

vanbox wrote: 1. will it be beneificial to power/torque?

It will change your power and torque. It depends on how it is constructed inside as to how the airflow is changed.

vanbox wrote: 2. will it increase/decrease/leave EGT's?

It shouldn't do anything to your EGT's as this there is minimal cooling of the intake air.

vanbox wrote:3. use more or less fuel?

This will only change how much fuel you use depending on the effects of question 1. How ever it will be minimal.

vanbox wrote:4. any other advantages/disadvantages to the way i want to do it?

The main advantage of a large plenum chamber is to calm the air and direct it to the right places for the best efficiency. It won't cool the air or change the fuel input enough to make a real difference.

vanbox wrote:would getting it re-tuned make a lot of difference. could i do it at a later date? any harm in running it as a bolt on for now...tune later?

If you are running 14psi already without tuning it then your engine is running lean and you are mostly wasting your time with the higher boost. If you run this plenum chamber then definately tune the engine. You may find that your fuel pump isn't delivering enough fuel and you'll ruin your engine if you lean it out. You haven't said if it is a GQ or GU fuel pump. They are different. You can get a little more out of a GU pump before having to change internal parts.

correct me if i am wrong but a lean diesel is a good diesel

lean diesel won't over heat = less power

more diesel = more power
more power = more heat (EGTs)